Electrical circuit-interrupter.



PATENTED DEG, 1L 1906. A. M. BULLARD & w. H. MATTHIES.

ELEGTRIGAL CIRCUIT INTEERUPTER.

APPLICATION FILED SEPT. 9 1905.

UNITED srarns Parana enrich.

ALBERT M. BULLARII AND WILLIAM H. MATTHIES, OF NEW YORK, N. Y.,

ASSIGNORQ TO WVESTERN ELECTRIC (lQhilPANY,

A CORPORATION OF ILLINOIS.

OF CHICAGO, lLLlh't llS,

ELECTFHGAL @lF-iCUl'l' lislTiEF-ERUPIER:

T all whom it may concern:

Be it known that we, ALBERT M. BULLARD and WILLIAM H. MA'rTIIIEs, citizens of the United States, residing at New York city, in

the county of New York and State of New York, have invented a certain new and use i'ul Improvement in Electrical Ci1'cuit-I nter 'rupters, of which the following is a full, clear, concise, and exact description.

In telephone-exchange systems the busy tone is more readily distinguished if itis intermittent or throbbing in. character rather than a continuous hum, for the latter is easily mistaken for the noise produced by induc- I 5 tion from electric-light circuits where the telephone-lines are not properly protected bptransposition.

Heretofore an interrupter has been used having a heavy weight on the arm to reduce -its vibrations to a comparatively slow periodicity. While such an arrangement can be operated in a manual exchange, where attention can be given at any time to its adjustment, at small automatic exchanges, where there is no 2 5 one in regular attendance, and, furthermore, where the interrupter is subject to low temperatures never encountered in manual exchanges, this type of interrupter has proven unreliable principally because the 0 extreme variations in temperature cause changes in the structure supporting the back contact, through which the current for the operation of the device passes The object of the present invention is to 5 provide a slow-acting circuit-breaker which can be operated at any temperature and which is self-starting, which starts promptly, and which operates on wide margins of adjustment. Instead of operating on the principle of mechanical inertia, as heretofore,

it utilizes electromagnetic inertia produced by a heavy closed copper secondarv encircling the iron core of the device.

The apparatus consists, preferably, of two 5 magnets or :elays, each having a heavy copper tube driven over its iron core and with the small Wire winding wound upon the cop per tube. The armature approaches and recedes from the pole-piece with a marked degree of sluggishnessa phenomenon well understood in the art.

Our'invcntion will be more reaon under- Specification of Letters Patent.

Application filed September 9,1905. Serial No 277.718.

Patented Dec. 11, 1906,

stood by reference to the accompanying drawings, in which- Figure 1 shows a diagram of two relays with circuits etnl'iodymg our invention 'Fig. 2 is a side elevation, with the casing in suitable for the work resection, of a relay quiredx It may be stated at the outset that the circuits of the relays are so designed that they alternately short-circuit each others winding, thus producing a slow reciprocating movement of each armature, which is util ized to make and break at regular intervals the bus -tone circuit leading to the switchboard.

Referring to Fig. i, when the battery-circuit is closed relay a operates its front contact l), and thus closes a circuit through relay 0, which attracts its arwatures, and in so doing closes contact (l, which causes relay 0 to remain thereafter locked up independent of contact 11 of relay a. Contact c of relay 0 short-circuits relay a, which thereupon releases its armatures, and its back contact f in trurn shortcircuits relay 0 and of course causes relay 0 to release its armatures regard less of the locking-circuit closed at contact (Z. Now the opening of contact 0 of relay 0 allows relay (1 to operate, thus beginning a second cycle identical with the first. Each cycle may occupy about one second of time. These cycles follow one another with great regularity and are kept from becoming too frequent by, first, the sluggishness of the copper-jacketed relays; second, by the shortcircuiting method of deenergizing the respective relays, and, third, by the plan of causingthesecond relay 0 to lock up. its armature, thereby permitting the armature of the iirst relay-that is, relay a to fully recover before current is diverted from relay 0. The resistance-coil g likewise tends to slow the reciprocative movement by reducing the amount of current used for the operation of the relay 0 and proportionate] T increasing the sluggishness of its armature movement. This resistance g also serves to prevent shorcircuiting of the battery when contact f of re lay a is closed. The resistance 72 is to prevent a ShCI'hrCII'GLlIl) of the battery when contact e is closed by relay 0. The switch is is for closing the battery-circuit to start the interrupter. The contact Z of the relay (1 is included in the circuit of' conductors m n, which may lead to a busy-tone apparatus and to the switchboard or mechanism oi the exchange, respectively, in a manner well understood. The purpose ol the combination of the two relays is to cause aretardation in the closing and opening of the contact Z, which is included in the tone-circuit. l

The apparatus as, thus described pauses cycles of about a one-half second duration. The time can be varied by adjustment oi the relays as may be thought most desirable. In Fig. 1 two armatures are shown simply for clcarness of illustration. In practice we have employed relays of the general character shown in Fig. 2, in which the contacts are'in the case of each relay controlled by a single armature.

This device works reliably at all temperatures found in practice. It is self-starting and assumes its normal frequency immediately. The changes infrequency due to variations of battery Voltage Within practical commercial limits are negligible.

We claim- 1. A circuit-interrupter comprising the combination with two relays and local circuits therefor, ofcontacts in said circuits controlled by said relays, whereby said relays recipeach others circuits and are alternately energized-and deenergized, and. an external busy tone circuit having a contact controlled by one of said relays, substantially as described.

' 2. In a circuit-interrupter, the combination with a relay and a circuit therefor, of a second relay having-a circuit with a contact adapted to be closed by the energization of said first relay, and a short circuit oi said relay having a contact adapted to be closed by the energization of said second relay, whereby said relays are alternately energized and denergized.

3. In a circuit-interrupt er, the combine-- tion with. a relay and a circuit therefor, of a cuits, of: a switch scconifl relay having a circuit controlled by said iii-st relay, a locking-circuit through said secmid relay having a contact closed by its cnei'gization, and a short circuit for each of said relays having normally open contact, that or the first being closed by the encrgization ol" said second relay and that of the second being closed by the dcenergization of said first relay, wl'iereby said relays reciprocally control each others circuits, and are alternately energized and (.lBCDOIglZGd.

4-. In'circuit-intcrrupter, the combination with two relays each having its winding included in a local circuit with a resistance, of contacts in said circuits controlled by said relays, whereby said relays reciprocally control each others circuits and are alternately energized and deinorgized, and an external busy-tone circuit having a contact controlled by one of said relays.

In a circnit-interrupter, the combination with two relays, a and. c, and their cir- 7; adapted to close the circuit ol? relay a, a contact b of relay a, a locking contact 01 of relay 0, each of said con tacts being adapted to close the circuit of the winding of relay. 6, contacts f. and 6, respectively reciprocaly cont-roiling the circuit through each other. s windings, and an external circuit having a contact controlled by one of said relays, whereby said relay is intermit tenztly energized to operate the contact of said external circuit. i I

In witness whereof we hereunto subscribe our names.

ALBERT lvL-BULLAED. /VILLIAIVI H. ELMITIIIIES. ii' itnesses to signature of Albert M. Bullard:

Dnl lirr O. Tania-En mouse Four.

/Vitnesses to signature of William II. liIat- JASON G. CRANE, l nnnir W. Moliq'rrnn. 

